[BillyM]

Allright.  I only recently started getting interested in high-end audio.  I have been lurking here for four of five months picking up on component matching, where to find deals, purchasing tips, etc.  I finally have a system complete enough to get a good feel for what sound I would like out of it, and start guessing on what needs work/replacement.

After reading quite a few reviews, I noticed BestBuy had one that was spoken fairly highly of; the Athena SF-2's.  Having a friend who works there, I was able to go in after-hours drag a chair up and really get to play with speaker placement and comparison between a few different brands.  After quite a long listen, I asked my friend what his price would be, and if he would be willing to pick a set up for me.  They are how cheap!?!     *buys then and there

...*fade to today*

They are in a noticably smaller room than the audition setup at BestBuy, and I have noticed some slight "thickness" in louder dynamic music.  A knowledgable acquiaintence suggested that I check into the speaker side-panel bracing.  Well, come to find out that is this speaker's main weakness.  The side panels are only 1/2" thick but 15"x47"!  That is some killer surface area.  IT makes sense, thin board, long spans, would create some outward noise.  

I cannot at this time employ acoustic treatment to the room, but I had an idea of bonding another 1/2" panel to the two side panels.  I wouldn't mind spending some more money on these speakers, seeing the great price I have gotten, so some custom woodwork would not be too far out of the question.  Has anyone done this?  Good/bad idea?  If that is out of the question, how about temporarially bonding some good thick acoustic foam to the side panels?  Would this achieve similar results?

[vpolineni]

so some custom woodwork would not be too far out of the question. Has anyone done this? Good/bad idea? If that is out of the question, how about temporarially bonding some good thick acoustic foam to the side panels? Would this achieve similar results?

both are great ideas... do a search for bracing. i think this topic was discussed in the vmps forum earlier.  my odyssey lorelei speakers do not have any bracing-instead they have acoustic foam lined all throughout the inside and it passed the "knuckle test" so I think either method will provide an improvement.  here's a pick of the foam lining the loreleis:


hope this helps.  good luck.

[BillyM]

*searched some more*

Wooden dowels inside the cabinet!  
Why didn't I think of that?!

Well, I'm off to void my 10yr warranty within 2 months of purchase.  Thank you for the reply, what sort of acoustic foam is that?  Purchase source?  I dont know what sort of acoustic damping is inside these speakers at present, but will check it out shortly.

Thanks again,
--BillyM

[bubba966]

Why not just line the inside of the walls with 2 layers of Dynamat Xtreme? You can get one of the big bulk packs off eBay for around $90, and that should take care of your two speakers rather well.

One layer of D'mat Xtreme kills vibrations very well. Two layers is is pretty nuts...

[Red Dragon Audio]

I like all these ideas and here is my variation:

Line the inside of the enclosure with premixed cement like this stuff.  Very cheap and shouldn't cost more than $20-$30 to do both speakers.  Just buy a bigger tub of it..what you see here is just a small one.



Then when that dries, put acoustic foam over that or even compressed fiberglass panels.

Then on the outside of the enclosure, do your idea of 1/2"-3/4" thick wooden panels.

This will give you four different layers.  The varying densities of these four  layers will help tame the resonances and tighten up that "thickness" you hear.

you may also want to experiment with a little loose fiberglass insulation stuffed inside.  It's cheap, easy to do and can have a very beneficial effect.

[BillyM]

Those are great ideas "heavystarch", but I see flaws in each that would keep me from doing them.  I am not trying to say that they wont work beautifully in your setup...

As for the cement, I would worry of it cracking/crubling off over time/temperature changes.  Winter vacation means temperatures down below 40deg, and summer AC off doors open means up to 90+deg.  

As for the loose fiberglass, the speakers are front ported...  I can see a few good hours of pounding bass from a movie or two filling the room with enough little fiberglass particles to be dangerous to the occupants health.  *itches*

I have yet to get a chance to pop open the speakers due to a VERY busy weekend, but will address the side panel supports soon with the wooden dowel and acoustic foam method.  Thank you all for your ideas and support.

--BillyM

[TheChairGuy]

Common modelling clay is real good for this purpose.  As you have to adhere it to the walls by pressing the clay flat, it doesn't really work on floor standers.....your hand won't or can't reach down far enough.

A bookshelf speaker will take about 5-6 lbs on average (at about $2 a lb).  You can find it at any craft or art supply store...they tend to be about $3 a lb.

I order from these guys - www.allartsupplies.com.  Plasticlay is $1.51 a lb package.  Get the gray colored pkg.....the black is a Plasticlay knockoff made in Mexico.  It, too, works....but smells, literally, like crap  

Do every wall inside, put a good dab on the crossover capacitor(s) and the (rear) of the woofer and tweeter basket.  The effect is darnright jaw-dropping all too often.  Has worked wonders on 3 sets of speakers used on.

The credit for this great tweek goes to Frank van Alstine.  He makes available, on his website (here at AC, or www.AVAHiFi.com) in pdf, his Audio Basics newsletter that he printed up for some time.  There is a lot to be learned there to increase your knowledge base.

As for acoustical damping, R19 seems to be favored by many...albeit, I too am squeemish about using it.  So, I buy some Acousta-stuf for $10.00 (I think it's free shippping on it, too, from the company that makes it). A 1 lb pkg is more than enough for a couple bookshelves.

$30 and about 3-4 hours of your time is what separates you from dramatically better sound.  Enjoy Billy  

[Red Dragon Audio]

Those are great ideas "heavystarch", but I see flaws in each that would keep me from doing them.  I am not trying to say that they wont work beautifully in your setup...

As for the cement, I would worry of it cracking/crubling off over time/temperature changes.  Winter vacation means temperatures down below 40deg, and summer AC off doors open means up to 90+deg.  

Well I guess I should ask; are these outdoor speakers or are they in a vacation home where you leave the heat off for the winter?  This cement is for outdoor use and should be able to withstand those tempuratures no problem.   To keep it from crumbling off, just  put a number of small nails here and there in the enclosure, so when the cement hardens, it has a little more to grip to.  The nails act like rebar in the foundation of your home.  

Here's an alternative if you don't want to use cement:You could use vinyl floor tiles which are quite heavy/dense and just glue them to the inside of the enclosure.  Do 2-4 layers of the tiles in the parts of the enclosure that are ringing the most. It is much cheaper than Dynamat and probably pretty close in terms of performance.  Only problem with heat is that they could peel off...so just get the staple gun out and tack 'em to the sides.  

As for the loose fiberglass, the speakers are front ported...  I can see a few good hours of pounding bass from a movie or two filling the  ...

 

I never had a problem with fiberglass shooting out of my subs, which moved plenty of air.   Here's why:
1) The Fiberglass wasn't placed in front of the port where the air movement is occuring so particles weren't being sucked/blown out the port and into the room.
2) My port was downward firing into carpet so any microscopic particles that might have escaped, were stuck in my carpet...under my sub.

However, that is a valid concern so I would simply suggest getting some cloth wrapped around the inside portion of the port and that should filter out any particulates that might escape.  Also don't place the fiberglass in the port.  Place it further away inside the enclosure and you won't have anything sneaking out with those two precautions.  (I have worked quite a bit with fiberglass in construction/remodeling and it's most dangerous when you are cutting it and directly handling it.  Once it's in place, it's really quite benign).  You could even go so far as to put it inside it's own cloth baggy inside the enclosure...an old pillow case would work great.

If the idea still is too bothersome, just get some polyfill at the local craft & fabric store.  It's a bit more expensive than fiberglass but works pretty good.

[TheChairGuy]

Billy, or anyone else interested in PlastiClay from AllArtSupplies...

I'm on their e-mail list (my wife is an art major and found their pricing to be the best she has seen on most things she buys) and, occasionally, they offer specials...

Here's one that brings the PlastiClay to about $1.40 per lb...

Hi

How about a pre-Christmas browse on www.allartsupplies.com.

The incentive, if you insert the coupon code 11304 you will receive an 11% discount.

This offer blows up on November 30, 2004. And do not forget to shop our "overstock"aisle for some great deals.

Happy hunting,

Bill S

Happy hunting indeed....